In many studies it was demonstrated that children are much more susceptible than adults for environmental toxic metal exposure. Hair analysis is a promising tool for routine clinical screening and diagnosis of heavy metal exposure and essential trace element states in the human body. Additionally it was demonstrated that oxidants and antioxidants play a central role in the pathogenesis of many pulmonary diseases including asthma. Furthermore, toxic metals, trace elements and oxidative stress have many pivotal role on immune system.